Hop aroma characterization of dry hopped beers using Headspace-Trap GC-MS

Abstract

In the brewing process hop is a major ingredient which provides a distinctive aroma and characteristic bitter taste. The breeding of new hop cultivars with a multitude of aromas and the increasing popularity of dry hopped beers called for detailed insights into beer aroma influenced by hop. Headspace sampling is a suitable technique for extraction of aroma compounds from complex matrices. The benefit of the use of a trap device in combination with headspace is the improvement of detection limits. In this study, a headspace (HS)-trap gas chromatography (GC)-mass spectrometry (MS) method was developed to study dry hopping aroma in beer. Analysis of monoterpenes, sesquiterpenes, terpene alcohols, esters, and ketones in various beer samples was performed. The influence of different hop cultivars (‘Mandarina Bavaria’, ‘Lemondrop’, ‘Bravo’, ‘Hallertau Cascade’, ‘Polaris’, ‘Smaragd’, ‘Saphir’, ‘Calypso’, and ‘Hallertau Blanc’) on the aroma profile of beer as well as the impact of hop addition time for the hop cultivar ‘Lemondrop’ was investigated. The HS-trap GC-MS technique covers a broad range of hop-derived aroma compounds and enables to monitor the volatiles during the whole brewing process.